Patent Application
20220118635
The following description relates to razor cartridges for a shaving devices, and more particularly to a razor cartridge having at least two blade assemblies that can have a positive or negative exposure relative to a support plane.
Shaving devices generally include a head unit having at least one or more cutting members or blades retained therein. The at least one or more cutting members or blades have cutting edges that are aligned in parallel when retained within the head unit.
Conventional shaving heads include a blade mounted on the upper surface of a blade support. The upper surface being understood as flat portion of the blade support which faces the shaving surface when in use. To avoid nicks and cuts using these configurations it is known to bring blade assemblies closer to each other. This also reduces the sense of irritation and enhances the glideness experience of the user during shaving. Document U.S. Pat. No. 8,117,753 discloses shaving heads having average inter-blade span not greater than 1.25 mm.
However, an inter-blade span smaller than 1.25 mm is a relatively small inter-blade span involving relatively small space available for water and shaving debris to flow between the cutting members and out of the razor (and shaving surface), i.e., rinsability.
Another method is to incorporate a separate spring element or adjustment element to control the exposure of the blade assemblies relative to the housing of the shaving head. Conventionally, a shaving plane is defined as a tangential line intersecting the first and second skin contact points (or simpler the highest points) of the shaving head. This is typically between the cap and guard on the housing of the shaving head.
The present disclosure provides a razor cartridge comprising a first blade support and a second blade support, each of the first and second blade supports include a flat portion having a lower surface and a front end. A support plane is tangent to the respective front ends of the first and second blade supports and the lower surface faces away from the support plane. A first blade is attached to the lower surface of the flat portion of the first blade support. The first and second blade supports include a base portion extending at an angle from the flat portion. The first blade includes a first cutting edge. A second blade is attached to the lower surface of the flat portion of the second blade support. The second blade includes a second cutting edge. The first and second cutting edges are offset with respect to the support plane.
The first and second cutting edges may have first and second cutting edge exposures that are between −80 μm to +80 μm with respect to the support plane.
The first and second cutting edge exposures may be between −45 μm to +45 μm with respect to the support plane.
At least one of the first and second cutting edge exposures may be negative with respect to the support plane.
At least one of the first and second cutting edge exposures may be positive with respect to the support plane.
A first distance between the first cutting edge and front end of the first blade support and/or a second distance between the second cutting edge and front end of the second blade support may be within a range of 0.3 to 0.7 mm.
The first and/or second distance may be between 0.4 to 0.6 mm.
The first and second distances may be the same.
The first and second distances may be different.
One or more front ends may be rounded.
A distance between the first cutting edge and the second cutting edge may be between 1.6 mm to 2.2 mm.
The angle β between the first and second blade supports base portion and flat portion may be within a range of 104° to 120°.
The razor cartridge may further comprise a third and a fourth blade support, each of the third and fourth blade supports may include a flat portion having a lower surface and a front end. The support plane may be tangent to the respective front ends of the third and fourth blade supports and the lower surfaces may face away from the support plane. The third and fourth blade supports include a base portion extending at an angle from the flat portion. A third blade may be attached to the lower surface of the flat portion of the third blade support. The third blade may include a third cutting edge. A fourth blade may be attached to the lower surface of the flat portion of the fourth blade support. The fourth blade may include a fourth cutting edge. The third and fourth cutting edges may be offset with respect to the support plane.
A third distance between the third cutting edge and front end of the third blade support and/or a fourth distance between the fourth cutting edge and front end of the fourth blade support may be within a range of 0.3 to 0.7 mm.
The third and fourth cutting edges may have respectively a third cutting edge exposure and a fourth cutting edge exposure that may be in the range between −80 μm to +80 μm with respect to the support plane.
According to the current disclosure a shaving head wherein the cutting element is mounted on the lower surface of the support (the surface facing away from a shaving surface when in use) and the cutting edge exposure is offset relative to a support plane defined by the front ends of the blade supports rather than the shaving head is provided. These configurations reduce the occurrence of nicks and cuts by providing additional contact points which increases the surface area that the shaving force is applied over the skin during shaving.
Furthermore, providing negative and/or positive cutting edge exposures enhances the control of the pressure applied to the skin. Positive cutting edge exposure results in a more aggressive shaving and therefore more pressure applied onto the skin by the cutting edge, while a negative cutting edge exposure applies a lower pressure to the skin and thus is better, e.g. for sensitive skin. This allows razor cartridges to be customized according to the various user needs and/or desires. For example, for users with sensitive skin a razor cartridge with negative cutting edge exposure would be more suitable, while a razor cartridge with positive cutting edge exposure would be more suitable for users mainly interested in a closer shaving with fewer strokes needed.
These configurations provide a large opening or spacing between the blades (IBS). Effective removal of the shaving debris and shaving foam during the shaving experience is achieved. This leads to less need for rinsing the shaver during a shaving experience as the increased IBS allows for a continuous flow of water, shaving debris, shaving foam thereby reducing the occurrence of clogging which improves the overall shaving experience because the shaving debris can now flow easily through the larger opening during shaving. This means that longer shaving strokes or more shaving strokes can be done before rinsing is needed. In addition, a user may not need to agitate or bang the shaver to dislodge debris during rinsing. This extends lifetime of the shavers, particularly as banging of the shaver to dislodge debris may undesirably change blade exposure.
The blade support 12 may include a base portion 12a and a flat portion 12b. The flat portion 12b may have a front end 12c. The flat portion 12b may extend at an angle α relative to the base portion 12a. The flat portion 12b may have an upper surface 12b′ and a lower surface 12b″ opposite the upper surface 12b′.
The blade 14 may include an upper surface 14a, a lower surface 14b opposite the upper surface 14a, and a cutting edge 14c. The lower surface 14b of the blade 14 may be attached to the upper surface 12b′ of the blade support 12.
Furthermore, a support plane S is defined by a tangent line to the front ends 12c of the blade supports. A cutting plane C is defined by a tangent line intersecting the cutting edges 14c of the blades 14. A cutting edge exposure E is defined as the vertical distance between the cutting plane C and the support plane S.
In this configuration shown in
Shown in
The blade support 120 may include a base portion 120a and a flat portion 120b. The flat portion 120b may have a front end 120c. The front end 120c may be flat or rounded. An aspect of having a rounded front end 120c is that it further increases the sliding of the blade assembly on the skin (shaving surface). This further contributes to improve glideness.
The flat portion 120b may extend at an angle β relative to the base portion 120a. The angle β between the flat portion 120b and the base portion 120a may be, for example, between 104° to 120°. The flat portion 120b may have an upper surface 120b′ that in use is a skin-facing surface and a lower surface 120b″ opposite the upper surface 120b′. The lower surface 120b″ in use faces away from a shaving surface, i.e. it faces away from the support plane S.
The blade 140 may include an upper or skin-facing surface 140a, a lower surface 140b opposite the upper surface 140a, and a cutting edge 140c. The upper surface 140a of the blade 140 may be attached to the lower surface 120b″ of the blade support 120. The blade 140 may have a thickness between 0.04-0.12 mm.
In this configuration shown in
As shown in
It is envisioned that all of the blade assemblies in a shaving head have the same distance dx, or same exposure. However, it is also envisioned that the blade assemblies in a shaving head have different distances dx and thus different exposures. For example, a shaving head may have a series of blade assemblies with increasing cutting edge exposure from the leading end to the trailing end of the shaving head.
If cutting edge is aligned with (or positioned at) the support plane (
It has been found that cutting edge exposures being negative or positive, i.e. not being neutral, may be desired in circumstances. For example, when the cutting edge exposure is negative relatively to the support plane S, a less aggressive shave is achieved. This is because the front end 120c of the blade support helps protect the shaving surface, e.g. skin, since the front end 120c of the flat portion 120b comes first in contact with the skin during shaving operation and then the blade cutting edge 140c follows contacting the skin. Therefore, the likelihood of irritation is decreased. Additionally, the life span of the blades is prolonged. For example, when the cutting edge exposure is positive relative to the support plane S, closeness and glideness is improved although skin irritation tends to be increased.
In particular, adjusting the cutting edge exposure facilitates enhanced control of the pressure applied to the skin. Positive cutting edge exposure results in a more aggressive shaving and therefore more pressure applied onto the skin by the cutting edge, while a negative cutting edge exposure applies a lower pressure to the skin and thus is better e.g. for sensitive skin. This allows razor cartridges to be customized according to the various user needs and/or desires. For example, for users with sensitive skin a razor cartridge with negative cutting edge exposure would be more suitable, while a razor cartridge with positive cutting edge exposure would be more suitable for users mainly interested in a closer shaving with fewer strokes needed. Razor cartridges combining negative and positive cutting edge exposures may also be foreseen.
It has been found that with the described ranges an effective balance between closeness and less irritation is succeeded.
Shown in
Shown in
The razor cartridge 1 may have a guard bar 3 and a rear cap 4. In examples, the razor cartridge 1 may not include the guard bar 3 and/or rear cap 2.
In the shaving direction, the guard bar 3 is shown in front of the blade assemblies 100 and the rear cap 4 is provided behind the blade assemblies 100.
The razor cartridge 2 may include at least two resilient elements 7 (for example spring fingers) elastically biasing each blade assembly 100 towards a rest position. In examples where the razor cartridge 2 includes a different number of blade assemblies 100, a corresponding number of resilient elements 7 may be foreseen. Accordingly, the blade assemblies 100 may be movable under forces encountered during shaving. The resilient elements 7 may be molded as a single piece with the head unit 5.
As aforementioned, the razor cartridge 2 may include fixed blade assemblies 100 that may not have resilient elements 7.
It has been found that a razor cartridge 2 including movable blade assemblies, as shown in the example of
In some examples of herein disclosed configurations a distance between consecutive cutting edges of adjoining blade assemblies (inter-blade span, IBS) may for example be between 1.6 mm to 2.2 mm, more specifically from 1.70 mm to 2 mm and most specifically from 1.75 to 1.95 mm. In an example, the IBS may be 1.85 mm±0.1 mm. This provide for a razor cartridge that is less prone to clogging thereby reducing rinsing necessity at the same time as customized razor cartridges may be provided.
An aspect of these examples is that a manufacturer can use existing standard head units traditionally used for housing five blade to house four blade assemblies. This can reduce the cost of razor cartridges while performance is at least maintained or even improved. Furthermore, if the blade assemblies are incorporated into existing standard head units, the manufacturer does not need to make major changes to their existing manufacturing process, therefore reducing the costs associated with a change over.
| Number | Date | Country | Kind |
|---|---|---|---|
| 19154896.5 | Jan 2019 | EP | regional |
This application is a National Stage Application of International Application No. PCT/EP2020/052166, filed on 29 Jan. 2020, now published as WO/2020/157132, and which claims priority to European Patent Application No. EP 19154896.5, filed on 31 Jan. 2019, entitled “RAZOR CARTRIDGE”, the entire contents of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/052166 | 1/29/2020 | WO | 00 |
